Asphalt is a material commonly used in conjunction with other materials for repairing roads, runways, driveways and other ground surfaces. Asphalt is a sticky, generally black and highly viscous liquid or semi-solid that is made from the residue of the distillation process used for crude oils, particularly petroleum. Asphalt may also be referred to as bitumen.
Asphalt is in particular used as a glue or binding substance for various types of aggregate particles. Asphalt is typically stored and transported at temperatures around 150 degrees Celsius (300° F.). It is important to maintain the liquidity of asphalt so that it can be evenly distributed on ground surfaces. Sometimes diesel oil or kerosene is combined with asphalt for shipping, and later separated. As a general rule, it takes approximately 8-12 minutes to properly heat and soften the asphalt. Heating time may vary depending on wind and temperature, moisture and humidity, and the composition of the asphalt material.
Once the temperature of the asphalt has exceeded 425 degrees, the rate of oxidation (evaporation of oils) is accelerated. At approximately 500 degrees, the asphalt actually starts to burn rendering it useless and guaranteeing the failure of the repair. Simply raking off the burnt asphalt will not remedy the situation because a portion of the existing heated asphalt must be left untouched so that the restoration can be rolled into a heated existing surface.
Methods for effectuating asphalt repairs and trucks with on-board heating systems for maintaining the liquidity of asphalt and effectively distributing it on ground surfaces are well known in the art.
U.S. Pat. No. 4,198,177, issued Apr. 15, 1980, teaches a “Method And Apparatus For Repair Of Asphalt Surfaces” and discloses a system for repairing asphalt surfaces which includes an emulsion tank, air pressure source, emulsion heating source, pneumatic tools, and a vehicle having a fluid-cooled engine and a utility body for containing asphalt repairing material. U.S. Pat. No. 4,423,980, issued Jan. 3, 1984, discloses a further improvement of an irremovably mounted asphalt tank for heating asphalt to a usable temperature. Certain of the pneumatic tools may be selectively driven by compressed air held in a storage tank to selectively heat and repair a damaged asphalt surface.
U.S. Pat. No. 5,419,654, issued May 30, 1995, discloses a vehicle with a telescoping tube assembly extendable between a maximum and a minimum overall length for patching operations and which may be compacted when not in use.
It is important to note, however, that each of the foregoing systems requires a complex assembly system installed on a vehicle specially designed for road repair and asphalt distribution.
Infrared asphalt repair technology has become increasingly popular. One commercially available vehicle having an infrared heating device is marketed by Kasi Infrared, a division of R. Filion Manufacturing, Inc., and is described at http://www.kasiinfrared.com/. This website describes the following infrared restoration method for heating and applying asphalt to ground surfaces using an infrared heating device: sweep away loose debris or standing water from repair and surrounding area; light the heating chamber and position it over the area to be repaired allowing at least 12″ of heated area beyond the perimeter of the repair; allow heat to penetrate for 7-10 minutes while checking surface temperature of the asphalt every 7 minutes; remove the heater and rake the softened asphalt; spray a substance on the heated area to replace some of the oil which has dissipated over time; apply fresh asphalt; and use a vibratory roller to compress the asphalt.
Infrared technology is viewed in the art as a superior form of asphalt repair. This technology avoids seams where the hot asphalt meets the cold pavement which allow water to penetrate the repair, causing the repaired filled-in portions to fail, typically within a year or so. Infrared technology blends new asphalt in with the original asphalt by heating an area 6 to 8 inches beyond the perimeter of the repair; the new asphalt is then compacted with the old creating a seamless permanent restoration.
A significant limitation, however, in using infrared technology has been the maneuverability and large size of the trucks that carry the systems. As a result, these trucks often cannot be used in tight spaces, close to buildings and other obstructions, and in other hard to reach areas. Small “walk behind” infrared heaters which are pushed by the user are available, but because of the smaller heater surface area, they take significantly longer to heat the asphalt and make the necessary repairs.
One particular limitation of infrared restoration vehicles with infrared heating devices attached is the difficulty of backing up the truck with the device in the lowered position. It is very difficult for the driver of the truck to judge how close the edge of the lowered infrared heating device is to a wall, garage door or other structure. Generally, backing up a truck with a lowered, mounted infrared heating device requires a human “spotter” to guide the person driving the truck. The spotter must let the driver know how close the extended infrared heating device is to the wall.
A further disadvantage of current technology mounted to vehicles is that as each area is repaired using an infrared, a “patchwork effect” is created, because it is difficult to see behind a vehicle to align each repair area.
It is desirable to have a method for using an infrared heating device for asphalt repair that does not require a spotter, because the spotter is needed to perform other necessary labor (e.g., raking or leveling), and which allows the spotter to devote their time and labor to quickly raking and leveling the previously heated areas.
It is aesthetically desirable to have an infrared heater mounting device that allows successive, symmetrical alignment of areas that are in a straight row and which need to be heated to avoid a “patchwork effect.”
It is desirable to be able to maneuver an infrared heating device around and close to a variety of structures (e.g., electrical boxes, walls, garage doors, protective poles and vehicle obstacles such as, tollbooths, monuments, fountains, curbs, etc.) The asphalt surrounding many of these structures is particularly susceptible.
It is further desirable to have a device which may be inexpensively manufactured and sold to adapt existing asphalt trucks or utility vehicles with infrared heaters resulting in increased maneuverability and mobility for positioning and patching of asphalt surfaces.